Involvement of S100A8/A9-TLR4-NLRP3 Inflammasome Pathway in Contrast-Induced Acute Kidney Injury

Background/Aims: Gastric cancer is considered as a common malignancy with a poor prognosis as well as unsatisfactory treatment. Neutrophil gelatinase-associated lipocalin (NGAL) has been reported to affect multiple aspects of human tumor, including gastric cancer. This study aims to explore the effects of NGAL gene silencing on the proliferation as well as apoptosis of human gastric cancer MGC-803 cells. Methods: This study included 87 patients with gastric cancer. MGC-803 cells were collected and mainly treated with siRNA against NGAL and recombinant NGAL plasmid. The expression of NGAL mRNA and the expressions of NGAL protein and apoptosis-related proteins were determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis, respectively. Cell cycle and apoptosis were tested by flow cytometry, and cell proliferation was detected by water soluble tetrazolium-1 (WST-1) assay. The effect of NGAL gene silencing on tumorigenicity of MGC-803 cells in vivo was detected through establishment of xenograft in nude mice. Results: NGAL was highly expressed in gastric cancer tissues. The protein and mRNA expressions of NGAL gene in MGC-803 cells treated with NGAL-siRNA were obviously reduced, and the amount of cells in G0/G1 phase was increased. Moreover, MGC-803 cells treated with NGAL-siRNA exhibited inhibited proliferation, enhanced apoptosis, decreased expressions of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) as well as B-cell lymphoma-2 (Bcl-2) and increased expressions of cysteine-aspartic acid specific protease-9 (caspase-9) and Bcl2-associated X (Bax), as well as repressed tumorigenicity in vivo. Conclusion: NGAL gene silencing inhibits proliferation and promotes apoptosis of MGC-803 cells, which can provide a novel theory for treatment of gastric cancer.

Section: Cellular Physiology and Biochemistrymentioning

confidence: 99%

Downregulation of NGAL is Required for the Inhibition of Proliferation and the Promotion of Apoptosis of Human Gastric Cancer MGC-803 Cells

Han

Nie

et al. 2018

“…Recently, studies have shown that renal ischemia, direct nephrotoxicity, and oxidative stress are responsible for the pathogenesis of CI-AKI [7, 8]. Our previous study showed that free radical scavengers, such as pentoxifylline, could effectively reduce reactive oxygen species (ROS), protecting the kidney from iodinated contrast-induced injury [9].…”

Section: Introductionmentioning

confidence: 99%

Mitophagy Plays a Protective Role in Iodinated Contrast-Induced Acute Renal Tubular Epithelial Cells Injury

Lei

Zhao

Tang

et al. 2018

Background/Aims: Contrast induced-acute kidney injury (CI-AKI) is one of the most common causes of acute kidney injury (AKI) in hospitalized patients. Mitophagy, the selective elimination of mitochondria via autophagy, is an important mechanism of mitochondrial quality control in physiological and pathological conditions. In this study, we aimed to determine effects of iohexol and iodixanol on mitochondrial reactive oxygen species (ROS), mitophagy and the potential role of mitophagy in CI-AKI cell models. Methods: Cell viability was measured by cell counting kit-8. Cell apoptosis, mitochondrial ROS and mitochondrial membrane potential were detected by western blot, MitoSOX fluorescence and TMRE staining respectively. Mitophagy was detected by the colocalization of LC3-FITC with MitoTracker Red, western blot and electronic microscope. Results: The results showed that mitophagy was induced in human renal tubular cells (HK-2 cells) under different concentrations of iodinated contrast media. Mitochondrial ROS displayed increased expression after the treatment. Rapamycin (Rap) enhanced mitophagy and alleviated contrast media induced HK-2 cells injury. In contrast, autophagy inhibitor 3-methyladenine (3-MA) down-regulated mitophagy and aggravated cells injury. Conclusions: Together, our finding indicates that iohexol and iodixanol contribute to the generation of mitochondrial ROS and mitophagy. The enhancement of mitophagy can effectively protect the kidney from iodinated contrast (iohexol)-induced renal tubular epithelial cells injury.

“…Contrast-induced nephropathy (CIN) is a frequent complication. The incidence of CIN varies from 3% to 14% and can reach as high as 20% in patients with high risk [2, 3]. Recent evidence suggests that CIN can cause long-term decline in renal function, leading to increased mortality [4, 5].…”

Section: Introductionmentioning

confidence: 99%

Tanshinone IIA Attenuates Contrast-Induced Nephropathy via Nrf2 Activation in Rats

Liang

Zhao

Cheng

et al. 2018

Background/Aims: Tanshinone IIA is a chemical compound extracted from Salvia miltiorrhiza Bunge, a perennial plant also known as red sage used in traditional Chinese medicine. Tanshinone IIA has been shown to protect against various organ injuries. In this study, we hypothesized that Tanshinone IIA could play an anti-oxidative role in contrast-induced nephropathy (CIN) through enhancing Nrf2/ARE activation. Methods: To test whether Tanshinone IIA can attenuate CIN, oxidative stress, and apoptosis, we utilized two models: an in vivo Sprague-Dawley rat model of ioversol-induced CIN and an in vitro cell model of oxidative stress in which HK2 cells, a human renal tubular cell line, are treated with hydrogen peroxide (H₂O₂). Rats were randomly assigned to 4 groups (n = 6 per group): control group, ioversol group (ioversol-induced CIN), vehicle group (ioversol-induced CIN rats pretreated with vehicle), and Tanshinone IIA group (ioversol-induced CIN rats pretreated with 25mg/kg Tanshinone IIA). Renal functions, renal injuries and apoptosis were evaluated by using serum creatinine, histological scoring, and TUNEL staning respectively. Malondialdehyde, 8-hydroxy-2’ –deoxyguanosine, and intracellular reactive oxygen species were used for oxidative stress assessment. Levels of Nrf2 and heme oxygenase-1 (HO-1) were measured in vivo and in vitro. Results: Tanshinone IIA attenuated renal tubular necrosis, apoptosis and oxidative stress in rats and oxidative stress in HK2 cells. Furthermore, Tanshinone IIA activated Nrf2, and up-regulated HO-1 expression in vivo and in vitro, resulting in a reduction in oxidative stress. Conclusion: Tanshinone IIA may protect against CIN through enhancing Nrf2/ARE activation.